Various types of systems, in which memory resources are virtualized and used, have been proposed so as to effectively utilize the memory resources in external virtual FC switches such as storages. For example, in the case in which a storage area network (SAN) which is a high-speed network used for connecting a host and a storage is established, there is a virtual FC switch which includes a function for inclusively virtualizing storage resources and causing the inclusively-virtualized storage resources to appear to be a new storage configuration, in addition to a function as a fibre channel (FC) switch which functions as a relay device.
The virtual FC switch has a function for configuring an arbitrary area of a connected physical storage device as a virtual disk and showing the virtual disk to the host through a virtual target (VT). In addition, the virtual FC switch has a function for copying data to another virtual disk configured in the same way.    [patent document 1] Japanese Laid-open Patent Publication No. 2006-127028